.mbtn {
    position: absolute;
    bottom: -.1rem;
    right: .16rem;
    display: flex;
    justify-content: space-around;
    align-items: center;
    width: .8rem;
    height: .5rem;
}

.mbtn>.click>span:first-child{
    width: .4rem;
    height: .5rem;
    position: absolute;
    left: 0;
    bottom: 0;
}
.mbtn>.click>span:last-child{
    position: absolute;
    right: 0;
    bottom: 0;
    width: .4rem;
    height: .5rem;
}
.mbtn>span:first-child {
    width: .21rem;
    height: .21rem;
    border-radius: 50%;
    box-sizing: border-box;
    border: 3px solid #00a0dc;
    margin-right: .1rem;
    flex: none;
    position: relative;
    transition: all .5s ease;
    transform: rotate(0deg);
    display: flex;
    justify-content: center;
    align-items: center;
    left: 0;
    opacity: 1;
}
.mbtn>span:first-child::after{
    content: '-';
    font-size: .25rem;
    color: #00a0dc;
}
.mbtn>span.cur-a0 {
    opacity: 0;
    left: .59rem;
    transform: rotate(180deg)
}
.mbtn>span:nth-child(2) {
    opacity: 1;
    width: .3rem;
    text-align: center;
}
.mbtn>span.cur-b0 {
    opacity: 0;
}
.mbtn>span.add {
    box-sizing: border-box;
    flex: none;
    color: #fff;
    display: flex;
    justify-content: center;
    align-items: center;
    width: .21rem;
    height: .21rem;
    border-radius: 50%;
    margin-left: .1rem;
    background: #00a0dc;
    z-index: 1;
}
.mbtn>span.add::after {
    content: '+';
    font-size: .25rem;
    color: #fff;
}
